Vernier dial



March 2 926 ,575,53

v J. F. DoBBxNs VERNIER DIAL Filed Oct. 2O l 1925 Patented Mar. 2, 192,6.

UNITED sr'aras Waise PATENT ortica.

JAMES IF. lDOBBIIIIIS,` OF BROOKLYN, NEW' YORK..

VERNIER nur..

Application filed October 20, 1925. Serial No. 63,584.

To all whom t may concern:

Be it known that I, JAMES F. DoBBINs, a citizen of the United States of America,.re siding at Brooklyn, in the county of Kings and -State of Newl York, have invented certain new and useful Improvements in Vernier Dials,of which the following is a specification.

This invention relates to an improved adjusting means for radio dials, such as are used on radio receiving sets to adjust the variable condenser, variometer, coupler, etc. In most cases the adjustment is effected by turningthe dial directly with the hand, but it is often extremely diflicultto obtain accurate tuning by this method, as the dials are generally made with a fair amount'of friction, so that when lsuiicient pressure is applied to overcome the friction, the dial moves farther than anticipated.

I am aware that reduction gears of various forms have been proposed to overcome this difficulty, but, with such gear, it is usually impossible tov get a quick adjustment of the dial through a large angle, which is often desirable. y

@ne purpose of my invention is to devise a radio dial in which the fine adjustment may be made accurately and the coarse adjustment quickly, all through the same hana dle or finger iece.

Another o ject of the invention is to simplify devices of this character so that the same may be made cheaply and without special gear cutting machinery.

From the description of the principle of my invention which follows, it will be apparent that it has other ap lications than I to radio dials, being adapte to the adjustment of any spindle where both accurate and wide range of adjustment is required.

Referring to the dna-wings in which what I now consider a preferred form of my invention is shown Fig. 1 is a plan view of a radio dial constructed according to 'my invention.

Fig. 2 is a side elevation of the same.

Fig. 3 is a vertical section on line 3 3 of Fia. l.

Fig. '4;v is a detail, 'and Fig. 5 is a front view of the adjusting pinion.

The dial proper 1 may be provided with .the usual graduations 2 denoting wave lengths. It is shown as provided with a central boss 3, having a` downwardly facing bore 4 in which is secured al metallic sleeve 5 for mounting it on a spindle (not shown). A set screw 6 may be used to clamp it to the spindle. Around the edge of the dial or disc 1,' I vprovide bevel gear teeth 6. Said teeth need not be accurately cut but may be in the form of radial knurling or raised graduations on the beveled outer edge 7 ofthe disc or any form of surface which will prevent slippage.

Journaled on the sleeve 5 is 'an arm 8 having an upwardly extending outer end 9 on which is rotatably mounted, as by means of pin 10, a bevel pinion`11. The lower end of sleeve 5 may be burred over to hold the arm 8 thereon. Said inion meshes with the teeth 6 on disc l an like it is provided with teeth 12 which may be in the form of knurling on the same pitch as the teeth-6', or other form of surface to prevent slippage between the gears.

The face of the pinion 11 is also provided with Vernier graduations 13 which are designed to read to the units or decimals of the numbers on the main dial. By this means the fine graduation's on the main dial may he omitted, the operation Idepending on the graduations on the smaller gear for this purpose,

From the foreging the operation of my invention will be readily apparent. All adjustments of the dial are secured by grasping theJ pinion 11 with the fingers, the teeth on the same giving one a good purchase. If a large movement is desired, the operator swings the arm 8 bodily around on sleeve 5 carrying the Idial with it by preventing the pinion from turning on its own axis as he revolves it with the arm. 'On the other hand, when line adjustment is desired, the operator-turns the pinion on its own axis so as to revolve the dial slowly and with extreme precision. The bevel pinion forms an ideal operating handle for. the purpose as it is located above and near the edge of the main dial. If desired, the bent u portion 9 on which the inion is journale may be made heavier as y providing additional weight at that point, so that said arm l8 will also hang vertically downward from pivot 5 like a pendulum.

In accordance with the provisions of the patent statutes, I have herein described the principle and operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereao-v of, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the combination and relations described, some of thesemay be altered and others omitted without interferingvvith the more general results outlined, and the invention extends to such use.

Having described my invention, what I claim and desire to secure by Letters Patent 1s:

1. An adjusting means for radio dials and the like comprising the combination with the dial mounted for rotation about an axis, of an arm swiveled on said axis, and a bevel gear rotatably mounted on said. arm and contacting .with the top of said dial.

2. An adjusting means for radio dials and the like comprising. the combination with the dial mounted for rotation about an axisand having bevel teeth on the top thereof, of an-arm swiveled on said axis, and |a bevel gear rotatably mounted on said arm )and meshing with the teeth on said dial.

3.v An adjusting means for radio dialsand the .like comprising the combination with the graduated dial mounted for rotation about an axis, of an arm swiveled on said axis, and a bevel gear rotatably mounted on said arm and contacting with the top of said dial,

said bevel gear being provided with gradi Yabout 4an axis and having bevel teeth on the top thereof, of an arm swiveled on said axis, and a bevel gear rotatably mounted on said arm and meshing with the teeth on said dial, said bevel gear being provided with graduations of lesser value than thegraduations on said dial.

5. An adjusting means for radio dials and the like comprising the combination with the dial mounted for rotation about an axis, of an arm sWiv'eled on said axis, 'and a gear rotatably mounted on said arm and contacting with said dial, said gear being so located that it may serve as the finger piece.

` 6. An ,adjusting means for radio dials and the like comprising the combination with the dial mounted for rotation about an axis,`of an arm swiveled on said axis, said arm beingmade heavier adjacent its outer end, and a'gear rotatably mounted on said arm and connecting with said dial, said gear being so located that it may serve as the finger 60 piece.

In testimony whereof I have aixed my signature.

JAMES F. DOBBINS. 

